The Supreme Court has started a new term, beginning a year that will perhaps force it to resolve the constitutionality of affirmative action, the legal status of same-sex marriage and a range of Fourth Amendment issues that have percolated up through the criminal justice system.

All of which reminds us that five is the most powerful number in the nation. Five votes on the Supreme Court can pick a president (recall Bush vs. Gore), redefine our constitutional rights (think Citizens United) and determine the constitutionality of a statute (remember last June’s healthcare decision). As Congress and the executive branch have proven themselves too often mired in gridlock and avoidance behavior in recent years, the Supreme Court has emerged as our most decisive branch of government.

But the old mythology that the Supreme Court can depend upon a neutral analysis of legal principles to resolve these tough issues is more and more suspect. The court itself has been mired in what often seems to be little more than ideological bickering. Witness the acid tone of the four conservative justices in their dissent in the healthcare case.

This partisanship — and the intellectual gamesmanship of those who erect false interpretive facades to justify outcome-oriented reasoning — detracts from the historic role of our final and most august deliberative body.

Yet even as one who wants to believe in the majesty of the law, I must acknowledge that the court has always been little more than a reflection of the time in which it serves. In the 1870s, it was grossly protective of corporate power and trusts. In the early 1900s, it was hostile to any form of collective action by workers. In the 1950s — finally — it blazed a trail for integration and recognition that separate is inherently unequal. In the 1960s, it opened new vistas of civil rights for individuals. Now, like much of the nation, it is polarized, while tending toward what is viewed as a “conservative” worldview.

The court over its history has given us both euphoric moments of progress and unfortunate stagnation. The term ahead will probably be no different. Here’s to hoping that Justices Breyer, Ginsburg, Sotomayor and Kagan can find the fifth vote they need in the critical cases to move us forward, not backward.

Eliot Spitzer, former governor of New York, hosts “Viewpoint” on Current TV.